


Corrosion

by KimberlyLikesCherries



Series: The Path to Yellow [10]
Category: Undertale (Video Game)
Genre: Curiosity killed the cat, Nudity, Sick Character, but satisfaction brought it back, its literally bones tho, mention of bugs crawling, mentions of depression, nothing remotely sexual here, sick fic...?
Language: English
Status: Completed
Published: 2020-07-08
Updated: 2020-07-08
Packaged: 2021-03-04 19:13:39
Rating: Mature
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,540
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25141459
Author URL: https://archiveofourown.org/users/KimberlyLikesCherries/pseuds/KimberlyLikesCherries
Summary: Pssst, guess what? July 8th is my birthday!Happy birthday to me, happy birthday to me~!
Relationships: Nightmare/Sans (OC)/Dream
Series: The Path to Yellow [10]
Series URL: https://archiveofourown.org/series/1706509
Comments: 35
Kudos: 67





	Corrosion

**Author's Note:**

> Pssst, guess what? July 8th is my birthday!  
> Happy birthday to me, happy birthday to me~!

Out on the edge of Snowdin in his sentry station, Sans and his datemate chilled out in silence.

Normally Sans would be doing something- writing, punning, training his magic- but, well, he wasn’t really feeling it right now. He wasn’t really feeling anything right now, except tired; but he couldn’t sleep so eventually he found himself just...staring. First at the wood grain under his arms, then the patterns on the pine trees, and eventually he settled on watching a lazily swishing tendril as it wandered side to side in front of him.

It made him wonder.

“What’s it like?” Sans nodded to Nightmare’s tendrils, “Being perpetually covered in goop?”

Nightmare, sitting on the countertop like the heathen he secretly was under all that goop, raised a brow, **“Why do you ask?”**

The taller shrugged, laying his skull on his crossed arms and staring back out into the tree line, “Seems sort of a pain; showers have got to be super messy.”

**“Heh!”** The dark guardian smirked, **“Wouldn’t you like to know?”**

Sans shot him a halfhearted finger gun, “Ey.”

The silence turned awkward; this was usually where Sans either flirted or punned back at the smaller skeleton, but he, well, didn’t have anything clever to say right now.

Nightmare turned to face him, one leg folding under him while the other hung off the edge. Sans could see him frowning down at him from the corner of his socket.

**“Is something wrong?”** Nightmare asked quietly, **“You feel upset.”**

Sans shrugged, “Just...didn’t sleep well.”

Nightmare stared at him a bit more before sighing, **“Give me your hand.”**

It took a second for the request to register, but once he understood Sans fished out his left from under his right arm and laid it out flat on the countertop, palm up. He expected the other skeleton to use his tendrils like he normally did, but instead Nightmare actually used his hands; it was somewhat startling.

**“Don’t panic.”** Was all he said before the negativity started  _traveling up Sans’ arm._

Visually, it was pretty tame- just some slimy substance coating his arm; he’d had worse that one time he went to see Alphys- but  _physically?_

Bugs. Thousands of bugs. They got about halfway up his upper arm before he couldn’t take anymore.

“Nightmare; Nightmare, _stop_. Nightmare, I’m ser-PANICKING!” He cried, arm wrenching free from his datemate’s grip and desperately trying to shake the goop off- without much success.

**“No!”** Nightmare yelped, literally launching for the effected arm, **“Damn it, I told you not to!”** Except by the time he got Sans’ arm back, the goop had mysteriously dissolved away.

The two locked lights, sockets wide.

“...Nightmare, what the fuck just happened?”

**“I-...”** The guardian looked genuinely worried, **“I have no idea.”**

———————————————————

Days passed but Nightmare never once relaxed. He actually went the complete opposite direction, going so far as to talk to his brother in private- though Sans wasn’t informed of what.

The taller wasn’t sure why Nightmare was so tense though; Sans was fine! Sure, maybe he wasn’t, you know, feeling all that great at the moment- but that was normal. Everyone got down in the dumps occasionally, you know?

(He tried really hard not to think of how little he’d been eating lately, or how just yesterday he tried to walk down the stairs and took a particularly rough tumble when a wave of dizziness hit him out of nowhere and caused him to misjudge the distance between steps.)

...though, Sans will admit that he’d been sleeping a lot; but that was just the depression kicking in. He always got really tired when he had an episode.

Atleast, that’s what he told himself; but today was the worst by far- like, to the point where every step felt like his knees would crumple under him and every sway shot nausea through his bones.  The room twisted and swirled around him like something out of a funhouse mirror maze, and if it weren’t for the fact that he had a death grip on the back of the couch Sans might have actually fallen over.

He-...he felt sick. Honest to Stars sick for the first time in probably, ever...?

(The thought echoed: He felt sick he felt sick he felt sick he felt-)

“Brother?”

Sans blinked slowly, turning his head at the same careful pace to Papyrus; not that it did him any good. Papyrus was just as incomprehensible as the warped world around the two, and turning his head felt more like letting the ground fly out from under his feet while also floating out into space all at the same time.

“...‘eah bro?” He slurred. It could have been a whisper, it could have been a shout; Sans honesty couldn’t tell, everything was getting so far away.

“Are you——?”

Sans stared blankly, “Wha-ht?”

“A— you —y?”

He jumped as a hand grabbed his sleeve, the skeleton’s thoughts scattering into the wind and shattering like a mirror.

(When did- sick, he feels- Had someone just been- Papyrus get so- sick, he feels sick- talking to him?- he feels- close?- so, so sick-!)

There were more voices around Sans now, more murmurs through the dull cotton in his skull. He could just barely register a dark hand prying his fingers out of the green upholstery Sans hadn’t known he’d still been holding onto, something gentle and cool wrapping around his waist- though failing to hold him up when Sans realized what those dark hands were trying to do and tried to help, but ultimately ended up pulling his hands back too quickly for his exhausted body to balance out in time.

**“Sans! -an you hea—e, -ans?”** A low voice called to him urgently next to where his ear would have been. He knew this voice, Sans knew he did, but it just (so sick, please-) wasn’t clicking.

Sans thought he heard someone ask him to stand up and he really did try, but just as he got both feet under him a huge wave of nausea sucker punched him right in the soul. He groaned and crumpled in on himself, or tried anyway; the voices tones changed in pitch drastically and for some reason his arms refused to fall to his sides.

“——?! ——!”

**“——, ———? ———-?”**

Cool little hands pushed against Sans chest, and when he blinked a frightened Papyrus was staring at him.

“...w’s wron...?” (Something’s wrong- Papyrus?- what’s going on- please, it’s so hot-)

Focusing as hard as he could through the spinning in his skull, Sans pushed out everything else to hear the little skeleton speak.

“You’re s—k —-ther, you need —-y d-wn!” He could just barely make out.

Lay down? But didn’t they just tell him to get up?

Before he could say anything back, a fresh wave of heat and dizziness sidetracked Sans into trying to curl into himself again.

“H-...hot...” he groaned out.

Something cool laid on the back of his neck vertebrae. Then, as he sighed and exposed his neck more to the thing, more of those same things wrapped around him; his arms, his back, and (much to his relief) Sans’ face was included on this list, though that was more around his forehead than anything else.

With something else to focus on, the worst of his ailments dulled into background noise with the world around him; and from one blink to the next, Sans nodded off into a dead sleep.

———————————————————

**Slooooosh...slooooosh...**

Sans bare feet dragged through the mucky waters, big toes occasionally scraping against the muddy bottom as he moved. Did it hurt? He didn’t know.

**Slooooosh...slooooosh...**

Something under his sternum ached; pulsing and twisted into an unrecognizable mass. His body bowed under the weight of some unseen burden laying on his shoulders

And yet, he walked.

**Slooooosh...slooooosh...Shlop!**

Ah, he tripped.

Sans shakily pushed himself back to his hands and knees, then to his feet with a stumble; not really wanting to, but knowing he couldn’t stop moving.

His limbs throbbed with strain, and once he was stable Sans found them unresponsive. The muck clung to the joints of his bare bones, staining his body and holding him in place as it whispered reassurances to him. The best he could get was a twitch from his fingers and toes.

_Stay. Stay. We have you, we’ll take care of you. Stay, and we’ll keep you. Safe. Loved._

“No...” he whispered, “No, I-...I can’t stop...”

_Why?_

The question echoed around him in the night sky; close, distant, soft, and so, so loving- as if proving it could be.

Sans found himself unable to respond, reasons leaving as the oil shaded waters seemed to reach up from it’s bed for him. He could do nothing but watch; and the farther up his body it climbed, the less he cared.

Why did he need to keep going? Did it matter anymore? If he walked just a bit further, would it change anything at all?

The murk, like slime given sentience, flung globes of itself higher up his legs; piling on top of itself as it pulled him in. Sans felt his feet begin to sink under the muddy floor.

It occurred to him that this may very well end him. Hurt and tired he may be, but a fool he was not; if he let this continue, if he let himself be swallowed whole, there would be nothing left of Sans.

There would be nothing left of him.

“——!”

Sans blinked, staring down at his limp hands. For a moment it has sounded like someone else was calling out in this unending sea of despair, something that set his soul just the littlest bit lighter; so he used what little strength he had left to lift his head and look over his shoulder-

_Don’t look away from me._

-but an oil slick hand reached out and pulled his head gently back around, soft like a lover’s caress. Something that looked like himself standing before him, naked just like Sans but obviously made of the black substance that surrounded him; It made no attempts to hide it’s nature.

He knew it for what it was, and it knew him for all he could have been, was, and would be- just as Sans knew. They were both aware of him, because they both were him.

This place, this unending moonless night in a sea of star reflected oil where the only real light was the dim soul in his ribcage- it was all his, him, them.

_Stay here, stay with me._

“——!”

Again. In the distance behind him, but closer? He didn’t bother to look, but the other him sneered at a spot over Sans’ shoulder and slid in closer, hands and arms flowing around his shoulders and cradling the back of his skull as it guided him to it’s shoulder.

_They say they want you,_ it spoke to the side of his skull, _but for how long? Will they abandon you the moment you don’t agree?_

Sans didn’t know.

_Stay here, with me. I will never leave, and you will never be discarded again._

Sans let his sockets drift to the hungry muck below, letting himself relax into the other’s hold. It purred, pleased as they submerged further into itself.

“Sans!”

The waters rippled past his knees, turbulent in a way they weren’t a moment ago- as if disturbed, or angered. His copy’s grip on Sans tightened, a hiss building up as wet footfalls echoed towards them.

On his back a heat he hadn’t noticed missing grew; with it, vague memories of a great light and laying on heated fabric as he drifted into a much appreciated nap. The ache in his beaten soul eased, but the one in his arms only grew stronger- this time with an almost choking feeling of longing.

“SANS!”

As they got closer, those echoing steps slowly became the sounds of two pairs of feet, both running full tilt towards him. The relief it inspired in him was enough to make his knees weak, and he most definitely would have collapsed had his legs not been almost completely swallowed in mud.

“It’s them...” he breathed, though not sure of who he was meaning in the slightest, “They came...for me...?”

His other’s hissing reached a reverberated crescendo, but true to it’s promise it did not leave; but then, it didn’t have to.

The cries of his name were suddenly drowned out by a great, deafening roar. A strong wind swirling around, kicking up oil black like saw blades around them and a smell like humid air and copper.

When Sans looked into those waves, memories- moments of time where colors had melted away and static had devoured every happy sound- where white noise couldn’t cover the words of other’s played in an unending loop.

He wondered if those two could see it too. Could they see his pain? Hear his fears?...suppose it doesn’t matter though, does it?

Though it hissed and raged, his other still took the time to rest it’s cheek against Sans shoulder; and with a start he realized they’re positions had switched.

It was scared.

He was scared.

“...we will be-“ he hesitated, then started over, “It...will be okay.”

_You can’t know that._

“No, but I...I want to believe. In them.”

_...will you ignore me again?_

“I spent...so much time saying it was okay; telling others it wasn’t a bad thing to feel you- but I never practiced what I preached, did I?”

A bitter laugh, a sob. From him or it, it was hard to tell; but it didn’t matter. They held each other tightly.

Light blasted through the waves; and through the settling mist of water, a burning glow of two bright lights.

Dream was the first to take off through it, every step sizzling the waters as he ran impossibly across the ocean surface, bow gripped tightly in a resting position at his side; Nightmare catching up a moment later, the waters more accepting of moonlight.

“Sans! Sans!” They called. Moments later Sans’ dark copy melted into him, dodging another arrow of positivity- and then two pairs of hands began pulling at him, desperate to free him from the mud.

It wasn’t easy, not by a long shot; and to make things less complicated Sans let himself go limp- but that only seemed to make them more frantic than they already were, and Sans heard more than one mutter of “No, no, no-!” and, “Not you too! I won’t let you!” before his legs finally popped free.

Momentum took over and all three ended up sprawled out on top of the star shining waters, the twins’ glow reflecting off like cut obsidian in the sun- and then Sans got a face full of terrified guardians, a pair of grey shaking hands coming up to hold his face between them.

“Sans, Sans does anything hurt? Do you know who I am?” Nightmare asked urgently, passive form on full display.

Dream was just about to ask something too, but Sans had other ideas. The two let out twin yelps as they were suddenly pulled down to his bare chest and wrapped in oil stained arms.

And then he woke up.

**Author's Note:**

> *floss dances to assert dominance*


End file.
